Decent cheap PA for singer

My band just recently got a new singer and unlike the last one, this one doesnt own any sinigng equipment. I dont know anything about this so basically what does he need besides a mic. We're talkin just for band practice in a room, no gigging things.

I like the Peavey Escort 2000. 150 watts, 5 channels, eq with feedback locators, mic, all cabling, and it all folds up into a package the size of a suitcase (ok a big suitcase but...) And it's reasonable.

I too have questions about this stuff, so I'll be watching the thread closely. I did some shopping on line and to me it seems to come down to; How much power do you need? For example - I've noticed that a person can pick up complete PA systems from low end manufacturers such as Kustom or Squier by Fender pretty cheap. They are around $200 and have low power ratings on the amps and small speakers in the monitors - about 80 watts and 10" speakers. Are those systems big enough to be useful? Would those little 80 watt PA systems be enough to amplify vocals in a small practice space enough that the vocals could be heard over a rock drummer and guitars and bass set to match the drummers volume. If the answer to that is no; then how much power would be enough for a practice PA just for rehearsals, not gigs? I hope I'm not steering the thread off track - I thought these questions fit right in so with the original post so I asked. I'll be watching.